Considering that he called Randy Carlyle a “stupid coach” on his way out of town, there is no doubt that Mikhail Grabovski’s relationship with the Toronto Maple Leafs’ bench boss had gone rotten.

Was buying Grabovski out the best course of action? That's debatable, considering how difficult it would be to trade a player with four years left at a $5.5 million cap hit. Regardless, removing Grabovski’s deal from the ledger freed general manager Dave Nonis, for better or for worse, to afford Tyler Bozak and David Clarkson in free agency.

The problem for Toronto is that, happy or not, Grabovski was remarkably effective. Over the past three seasons, according to data from hockeyanalysis.com, he played at least 60 minutes of 5-on-5 hockey against David Krejci, Milan Lucic, Jason Pominville, James Neal, Thomas Vanek, Tomas Plekanec, Milan Michalek, John Tavares, Matt Moulson, Kyle Okposo, Alex Ovechkin, Daniel Alfredsson, Evgeni Malkin, Chris Kunitz, Blake Wheeler, Lars Eller, and Jason Spezza. In that time, facing some of the top offensive talent in the Eastern Conference, Grabovski had a 53.5 percent Corsi rate, the percentage of shot attempts for and against the Leafs when he was on the ice. Over that three-year stretch, the Maple Leafs had a cumulative team Corsi rate of 47.4 percent. With Grabovski on the ice, playing a mostly defensive role, the Leafs’ possession rate was 5.9 points better, and on the right side of 50 percent.

Over the 48-game season that concluded in April, the swing was just 0.2 points: The Leafs had a 44.1 percent Corsi rate and Grabovski’s was 44.3 percent. But it’s also worth considering who Grabovski was playing with—his primary linemates for the season were Nikolai Kulemin and Jay McClement. With Grabovski, Kulemin had a 42.7 percent Corsi rate, compared to 38.3 percent without him. More might be expected from McClement, but his sixth-place finish in the Selke Trophy vote was mostly for his work as a penalty killer. At 5-on-5, McClement had a 42.2 percent Corsi rate playing with Grabovski, compared to an astonishingly low 29.1 percent without him.

Presumably, the plan in Toronto is to replace Grabovski with Dave Bolland, who was acquired from the Chicago Blackhawks for a second-round draft pick and two fourths. If this were three years ago, that would make plenty of sense. From 2007-08 through 2009-10, Grabovski played 161 games for the Canadiens and Maple Leafs, while Bolland played 159 for the Blackhawks. Grabovski had an 0.20-0.18 advantage in goals per game, an 0.37-0.32 advantage in assists per game, and a 53.0-52.8 advantage in Corsi rate. Those marginal advantages, were they present from 2011-13, would be enough to justify the more than $2 million in cap savings for this year before Bolland hits free agency next summer.

The Leafs, however, are not only looking back beyond three years as they make plans for Grabovski. They are looking back much further.

"If you go back and look at (Bolland's) junior numbers, they're exceptional," Nonis told reporters at the NHL draft, referencing the 299 points Bolland scored during 254 games with the London Knights of the Ontario Hockey League. "He played behind some pretty good people (in Chicago) and I think Randy won't pigeon-hole him as a third-line center. I think he'll probably be put in more of a prominent role with us than he was in Chicago."

This line of thinking has two problems. One is that Grabovski's and Bolland's careers have dovetailed over the last three seasons.

Grabovski has been remarkably durable, missing only nine regular-season games; Bolland has missed 40, including time out with a concussion. Both players have seen their goal rates go up, but Grabovski’s has risen more, to 0.30 per game compared to 0.24 for Bolland, while both players’ assist rates have gone down, as Grabovski has a 0.32-0.27 edge over Bolland over the past three seasons. The players’ Corsi rates in that time have diverged, with Grabovski improving to 53.5 percent for a Toronto team whose possession rates have generally been awful, and Bolland slipping to 47.9 percent for a Chicago team whose overall rate during that time was 53.1 percent. Bolland, like Grabovski, faced top competition. With Chicago the past three years, he played at least 60 minutes at 5-on-5 against David Legwand, Rick Nash, Henrik Sedin, Corey Perry, Justin Williams, David Backes, Ryan Getzlaf, Antoine Vermette, Patric Hornqvist, and Daniel Sedin.

The other problem with Nonis' theory that Carlyle won't "pigeon-hole" Bolland is that Joel Quenneville did not pigeon-hole him this year. Bolland played all but 33 minutes of his 5-on-5 time with Patrick Kane, who had a 45.0 percent Corsi rate with him, and 56.3 percent without, while Bolland's second-most frequent linemate, Patrick Sharp, had a 41.9 percent Corsi rate while skating with Bolland, compared to 59.8 percent without.Bolland's overall Corsi rate was 44.7 percent.

The Maple Leafs’ gamble is that Bolland, who at 27 is two years younger than Grabovski, will perform better with less talented linemates, which is counterintuitive, but at least the case could be made that playing with Kane and Sharp forced Bolland to play outside his comfort zone as he tried to keep up with two elite offensive wingers.

If Bolland is with, say, Clarkson and James van Riemsdyk, he will be flanked by wingers with skill, but not at the same level as Kane and Sharp. Meanwhile, putting Bolland in the top six would leave Nazem Kadri in the bottom six, a questionable decision in itself given Kadri's 44 points in 48 games last season, with a 47.1 percent Corsi rate that was three points better than the Leafs' as a team.